Plasticizers



Patented Au 1c, 1938- UNITED STATES PATENT OFF-ICE to The B. F. GoodrichCompany, New York,

N. Y., a corporation or New York No Drawing. Application June 25, 1937,Serial No. 150,327

Claims.

This invention relates to plasticizers and to plastic compositionscontaining them, and has as its principal object to provide a new classof plasticizers which impart desirable properties to compositions inwhich they are used. 7

Many of the recently developed synthetic plastic materials are organicresins which require plasticizers to render them less brittle and moreeasily workable. Plasticizers are also used in 10 lacquers and paintscontaining plastics to impart the desired flexibility to films formedtherefrom. Among the synthetic organic materials with which plasticizersare frequently used are included chlorinated rubber, urea-aldehyderesins, phenol-all-T- dehyde resins, cellulose esters and ethers,polystyrenes, and resins obtained by polymerizing vinyl or acrylicesters. While the plasticizers of this invention may be usedincorporated with organic resins in general, they are particularlyuseful in the polyvinyl halide compositions described in U. S. PatentNo. 1,929,453 issued to Waldo L.

Semon.

I have discovered that organic sulfones as a. class are excellentplasticizers. All of the compounds included within the scope of thisinvention have the structural formula 0 ll r-fi-dh where R1 and R2represent hydrocarbon or substituted hydrocarbon groups. Besides carbonand hydrogen, R1 and R2 may contain halogen, oxygen, and sulfone groups,but no others. Thus R may be selected from a large class of radicalsincluding methyl, ethyl, isopropyl, amyl, cyclohexyl, phenyl, ortho,meta, or para tolyl, xylyl, xenyl, alpha or beta naphthyl, benzyl,phenylethyl, naphthylmethyl, tetrahydronaphthyl, octahydronaphthyl,methoxymethyl, methoxyethyl, acetonyl, propionylmethyl,carbethoxymethyl, ethylsulfonylethyl, anisyl, phenethyl,phenylsulfonylmethyl, phenylsulfonylacetylmethyl, chloromethyl,chlorophenyl, chloronaphthyl and many other similar groups.

It is possible in some cases to use solid materials as plasticizers.Compositions containing them are apt to be still and boardy, however,and in general do not have the desirable properties obtainable whenliquid plasticizers are used. The sulfones wherein R1 and R; areidentical are usually solids when pure, but many of them may beliquefied by mixing them with isomeric or similar compounds to lower themelting point sufiiciently to form a. liquid material. Hydrogenation ofring structures, substituting halogen for hydrogen and adding an alkoxygroup usually tend to convert solid materials into more useful liquidplasticizers.

The preferred compounds are those sulfones in 5 which R1 contains anaromatic group and in which R2 is aliphatic. Ethyl beta-naphthylsulfone, Z-methoxyethyl beta-naphthyl sulfone, propionylmethyl p-tolylsulfone, carbethoxymethyl p-tolyl sulfone, and 2-methoxyethyl beta- 10naphthylmethyl sulfone are all materials which are very usefulplasticizers. v

The sulfones are easily prepared by wellknown methods, the mostconvenient being by the oxidation of the proper sulfide. To prepare i6ethyl beta-naphthyl sulfone, for instance, betathionaphthol is reactedwith ethyl chloride in the presence of sodium hydroxide to produce ethylbeta-naphthyl sulfide which may then be oxidized with hydrogen peroxideto ethyl betanaphthyl sulfone.

The plasticizers may be combined with the organic resins by any of theordinary methods. In the preparation of phenol-aldehyde resins, forinstance, the plasticizer is usually included in 25 the compositionbefore resinification occurs. Similarly, polyvinyl halides may bepolymerized in the presence of plasticizersto form plasticizedcompositions of the soluble polymers. It is usually desirable, however,to add the plasticizer to 30 the insoluble (gamma) polymer afterpolymerization. The plasticizer may be mixed with the powdered polyvinylchloride and the mixture may be homogenized on a heated roll mill or ina heated internal mixer. If desired, the polyvinyl chlo- 35 ride may bedissolved in the plasticizer or a mixture thereof with a volatilesolvent at elevated temperatures, usually from 100-150 C.

To illustrate the desirable properties imparted to compositions by theplasticizers of this inven- 40 tion, equal parts of gamma polyvinylchloride and Z-methoxyethyl-beta-naphthyl sulfone were homogenized on aheated roll mill. When this composition was molded in a press, acomposition having unusually high tensile strength and elonga- 45 tionwas obtained. The heat loss when the composition was heated in a hot airoven at 100 C. was much lower than the loss from compositions containingalmost any of the usual plasticizers.

The resistance of polyvinyl halide compositions 50 to petroleum solventsis well-known. Nevertheless, it has been found that compositionscontaining ordinary plasticizers eventually become stiller when used ingasoline and oils due to the extraction of plasticizers by the petroleumsolvents.

Compositions containing the plasticizers of this invention, however. areunusually resistant to pe- Polyvinyl halide compositions plasticizedwith 2-methoxyethyl beta-naphthyl sulione, for instance, are stiil'enedby gasoline only from one-halt to one-third as fast as those plasticizedwith tricresyl phosphate, and only one tenth as last as thoseplasticized with dibutyl phthalate.

It is to be understood that carbon black, clay, barytes, zinc oxide,wood flour, and other pigments and tillers commonly used in the rubberand plastics industries may be included in the organic resinouscompositions.

The plasticiaers of this invention may also be used in conjunction withother types of plasticizers, although this is generally undesirablebecause the commercially available plasticizers are interior and preventthe full advantages of these new plasticizers from being attained.

Although I have herein disclosed speciiic embodiments oi my invention, Ido not limit myself wholly thereto, for any modifications such as thesubstitution oi equivalent materials and the variation oi proportionsused are within the spirit and scope of the nvention as deilned in theappended claims.

I claim:

1. The method which polyvinyl halide with an 2. The method whichcomprises plasticizing a polyvinyl halide with a sulfone containing noother elements than carbon, hydrogen, oxygen, sulfur and a halogen.

3. The method which comprises plasticizing a polyvinyl halide with analiphatic aromatic sulione.

comprises plasticizing a organic suli'one.

4. The method which comprises plasticizing I polyvinyl halide with analkyl aryl sulione.

ii. The method which comprises plasticizing a polyvinyl halide with analkoxyalkyl-aryl sulfone 6. The method which comprises plasticizinggamma polyvinyl chloride with 2-methoxyethyl beta-naphthyl suli'one.

7. The method which comprises plasticizing gamma polyvinyl chloride withethyl beta-naphthyl suli'one.

8. The method which comprises plasticizing gamma polyvinyl chloride withZ-methoxyethyl beta-naphthylmethyl sulfone.

9. A plasticized composition comprising a polyvinyl halide and anorganic suli'one.

10. A plasticized composition comprising a polyvinyl halide and asulione containing no other elements than carbon, hydrogen, oxygen,sulfur, and a halogen.

11. A plasticized polyvinyl halide and

